package com.sky.service.impl;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.sky.constant.MessageConstant;
import com.sky.dto.UserLoginDTO;
import com.sky.entity.User;
import com.sky.exception.LoginFailedException;
import com.sky.mapper.UserMapper;
import com.sky.properties.WeChatProperties;
import com.sky.service.UserService;
import com.sky.utils.HttpClientUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.HashMap;

@Service
@Slf4j
public class UserServiceImpl implements UserService {
    private static final String WX_LOGIN = "https://api.weixin.qq.com/sns/jscode2session";

    @Autowired
    private WeChatProperties weChatProperties;
    @Autowired
    private UserMapper userMapper;

    /**
     * 此方法用于：发送请求，获取微信用户的 openid
     *
     * @param code 微信端发送的临时登录凭证
     * @return openid
     */
    private String getOpenId(String code) {
        HashMap<String, String> claim = new HashMap<>() {{
            put("appid", weChatProperties.getAppid());
            put("secret", weChatProperties.getSecret());
            put("js_code", code);
            put("grant_type", "authorization_code");
        }};

        String jsonStr = HttpClientUtil.doGet(WX_LOGIN, claim);
        JSONObject jsonObject = JSON.parseObject(jsonStr);
        return jsonObject.getString("openid");
    }

    /**
     * 此方法用于：微信登录
     *
     * @param userLoginDTO 微信登录参数
     * @return User
     */
    @Override
    public User userLogin(UserLoginDTO userLoginDTO) {
        // 调用微信接口服务，获得当前微信用户的 openId
        String code = userLoginDTO.getCode();
        String openid = getOpenId(code);

        // 判断 openId 是否为空，如果为空表示登录失败，抛出业务异常
        if (openid == null) throw new LoginFailedException(MessageConstant.LOGIN_FAILED);

        // 判断当前用户是否为新用户
        User user = userMapper.selectByOpenId(openid);

        // 如果是新用户，自动完成注册
        if (user == null) {
            user = User.builder()
                    .openid(openid)
                    .createTime(LocalDateTime.now())
                    .build();
            userMapper.insert(user);
        }

        // 返回这个用户对象。
        return user;
    }
}
